L-amino acids, such as those having the formula IV,
wherein R is H, alkyl or aryl and R1 and R2 are the same or different alkyl groups and wherein R1 and R2 may be fused, can be synthesized by using mono-acetal (ketal)-aldehydes. Synthesis of mono-acetal-aldehydes from dialdehydes suffers from complications in purification and low yields, particularly when the two formyl groups are equivalent. It is even more difficult to make ketal-aldehydes from ketoaldehydes because the formyl group is more reactive than the keto group. Hydroformylation of readily available olefinic acetals or olefinic ketals typically produces a desired linear aldehyde and undesired branched aldehydes. Separation of the linear mono-acetal aldehyde and the branched mono-acetal-aldehydes is generally very difficult due to high, similar boiling points.